Concrete!

…… and steel, and wood, and terracotta

The previous sections have described how the country emerged from World War 1 with a promise from Prime Minister Lloyd George of “Homes Fit for Heroes” but without any financial stimulus to kick-start the scheme. There was a lack of money and a rent freeze had made new housing potentially uneconomic to build. There was also a major skills shortage, particularly in brick making and laying. To overcome the latter the government turned to construction methods that did not require such skilled and time-consuming labour. It comes as a surprise to many people who see streets upon streets of plain white “council houses” that many of these are not simply brick houses, rendered, and painted white. Many are made of prefabricated concrete sections, or from concrete mouldings poured in-situ. Most will have been coated with a cement-based render to weatherproof the joints between the mouldings. Some post-WW1 houses are steel framed (concrete or steel-sheet walls), and a few were wooden framed. The latter were known to be unsuitable for British climate, but the need was such that they were built anyway and have lasted well. Replacing the standard 9” house brick with larger concrete blocks (say, equivalent to 9 house bricks) as in common use today, was not viewed as an alternate as this still needed skilled brick layers. The aim of using the new methods was to speed up construction and reduce the skills needed, hence the larger wall sections and an element of prefabrication. In many cases these “concrete” houses cost as much to build as the traditional brick equivalent. A few immediate-post-war schemes used terracotta blocks, very similar to those used in Mediterranean countries today, and rendered on the outside. This method was developed before the war and was meant to be cheaper to construct than other materials but the quality of the mortaring and rendering had to be high to withstand the damp British weather. This building material was not successful and soon passed out of use. Apart from terracotta blocks, most of the other non-traditional post-WW1 materials were successful and even the least successful survived 60 years before they became uneconomical to repair and had to be demolished. They may not have been pretty, but they were functional and many had good thermal qualities.

Developing alternate building materials
It was recognised towards the end of WW1 that there would be a skills shortage after WW1 in building materials and skilled labour. As early as 1916 the Department of Industrial & Scientific Research (DISR) was created to look into all materials research and by 1917 were established enough for them to create a sub-body called the Building Materials Research Committee (BMRC) to resolve the problem raised by the Tudor Waters report of that year that there was insufficient knowledge regarding alternate building materials. This commendable approach resulted in a committee with good engineers and with the notional support of the Local Government Board (LGB), but no finances. The Government wanted new methods to be used where they were needed, not just because they were cheaper.

1918: The research gets going
Despite the lack of finances and a lack of agreement as to the aims, the BMRC did carry out some good research in 1918 and came up with some extremely useful findings. Bear in mind at the time that the industry had little experience of prefabrication or small scale construction using concrete. Construction timber was put to a great deal of stress testing and jointing experiments. Concrete, in its widest sense, was also well researched and the results were that concrete that used slag or breeze for the aggregate had better thermal properties than stone or sand based aggregates because of the air trapped in the coarser aggregate material. This principle is well known now, but must have been a revelation at the time. They also discovered, as many soldiers in WW1 had, that concrete was also prone to retaining the damp. The research eventually led to the discovery that a cavity between the inner and outer wall of a building would retain the heat and repel dampness better than a solid wall. The scale of improvement, as published by the BMRC, was seen as being a little too good to be true and therefore was treated with some suspicion, but improvements there definitely were. The outcome was the general use of cavity walls for prefabricated buildings, post war, and the use of “No Fines” aggregate – no fine material used (e.g. sand).

1919: War ends, building starts
With the government keen for authorities and private enterprise to start a major house building programme they were hoping that the materials research carried out by the BMRC would encourage the use of alternate materials to brick. If that was the case, they were to be disappointed. There was inter-departmental fighting between the various government bodies, including the new Ministry of Health. The BMRC was replaced by the Building Research Board (BRB) in 1919, which did nothing to speed things up – quite the opposite. The LGB were not part of this new Board and decided to do their own research.

1920: Wasted opportunities
The BRB continued to drag its feet and produced almost nothing of value. In the meantime, the Ministry of Health commissioned Sir Ernest Moir (Chairman of the Committee for Standardisation and New Methods of Construction) to produce a report on alternate building materials. Sir Ernest was a noted and respected engineer. His brief was to investigate new construction methods and equipment. His report made no recommendations but listed all the companies that could supply the different materials. Although the list included steel and timber frame construction, the majority were companies that used concrete and aggregates. Some of the materials and methods would raise modern eyebrows, but some company’s products were very sound and were eventually used to build houses. But without government recommendations and with the BRB dragging its feet, the opportunity was lost for immediate widespread use the new methods.

1921: Recommendations finally accepted, but too late
At last, in 1921, the BRB published the results of their scientific research. These, very much simplified, were that concrete was a viable building material for domestic housing especially regarding thermal efficiency and when used with cavity walls. But it was too late. These recommendations coincided with the financial slump and the removal of house building subsidies. Only in 1923, when subsidies were resumed, could the industry make use of the recommendations.

To the credit of the industry, it did so, and in large numbers from 1923. Concrete was by far the most common building material used as an alternate to bricks, but steel framing and even timber were used (the latter particularly on the LCC’s Watling Estate). The location of the factory providing the materials and skills had a great influence on where particular house types were built, with some very localised schemes, but some companies eventually built this “alternate” housing across Britain.